Photographic apparatus

ABSTRACT

An automatic shutter control system for a photographic camera having a removable film holder and viewing screen. When the film holder is attached to the camera, the shutter control system closes down the shutter. Removal of the film holder for viewing and focusing actuates the shutter control system for automatically opening the shutter to a full aperture position in which the available focusing light is maximized. The need for manually opening the shutter to its fully opened position just prior to focusing is thereby alleviated.

United States Patent 1191 Seiden Jan. 22, 1974 PHOTOGRAPHIC APPARATUSPrima ExaminerJohn M. Horan 75 l t M A. s h l men or ymn elden Need MassAttorney, Agent, or Firm-Brown and Mikulka [73] Assignee: PolaroidCorporation, Cambridge,

- Mass 57 ABSTRACT [22] Flled: Sept 1972 An automatic shutter controlsystem for a photo- [21] Appl. No.: 292,487 graphic camera having aremovable film holder and viewing screen. When the film holder isattached to the camera, the shutter control system closes down :Lfiil.the shutter Removal of the holder for viewing d 95/49 and focusingactuates the shutter control system for 1 le 0 care automatically ope gthe Shutter o a aperture position in which the available focusing lightis maxi- [561 References C'ted mized. The need for manually opening theshutter to UNITED STATES PATENTS its fully opened position just prior tofocusing is 2,397,742 4/1946 Kals 95/49 X thereby alleviated.

791,800 6/1905 Laura... 95/53 1,857,706. 5/1932 Zabrocki 95/49 5 Chums,3 Drawmg i PHOTOGRAPHIC APPARATUS BACKGROUND OF THE INVENTION maticshutter operation and a removable plate holder or film carrier attachedto a portion of the camera.

Under usual operating procedures, the shutter is manually opened, thecamera is focused, and the film carrier is attached to the camera justprior to exposure. Before exposing the film, however, the shutteropening must be set from the wide open focusing position to the desiredexposure setting. It is essential that this final step be performedprior to each exposure for well exposed photographs. Should the cameraoperator neglect to re-adjust the shutter, the shutter will be fullyopen during exposure and an overexposed photograph may result.

SUMMARY OF THE INVENTION The present invention is addressed to a camerahaving an automatic shutter control system for viewing. In the presentsystem, removal of the film carrier for viewing and focusing of theimage automatically holds the shutter open to a full aperture position.When the film carrier is attached to the camera, for taking aphotograph, the system automatically closes down the shutter so that thelatter may be operated in accordance with routine procedures.

In a preferred embodiment of the present invention, the camera includestwo shutter releases. One is uti lized for taking pictures while theother is employed for automatic control of the shutter during viewing.The latter shutter release is coupled by a conventional cable to asliding bar arrangement which is automatically displaced upon insertingthe film carrier in the camera. Consequently, the shutter isautomatically opened when the film carrier is removed from the cameraand is closed upon re-insertion of the film carrier in the camerawithout the need for manual closing of the shutter subsequent tofocusing. It should be noted that the present invention is operative toautomatically control a diaphragm in much the same way as it controlsthe shutter. Accordingly, while the term shutter is used throughout thisspecification, it is intended that the invention relates to a diaphragmcontrol system as well.

OBJECTS OF THE INVENTION It is a general object and feature of thepresent invention to provide a camera having an automatic shuttercontrol system for viewing an image to be photographed.

Another object and feature of the present invention is to provide acamera having an automatic shutter control system which automaticallyopens the shutter when the camera's film carrier is removed from thecamera and which automatically closes the shutter when the cameras filmcarrier is inserted into the camera.

Further obects, features and advantages of the invention will in part beobvious and will in part become apparent as the following descriptionproceeds. The features of novelty which characterize the invention willbe pointed out with particularity in the claims annexed to and forming apart of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of a portion ofthe present invention with portions broken away to reveal internaldetail; FIG. 2 is a side view of the apparatus of FIG. 1; and FIG. 3 isa schematic of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS Looking to FIGS. 1 and 2, there isshown a camera back 10 adapted for use with a multi-purpose camera, arear portion of which is shown as at 12. Camera back 10 includes acamera back adapter assembly 14 suitably formed for attachment to thecameras rear portion 12. Back 10 is retained to portion 12 through apair of latching arms 16 positioned on the lateral edges of assembly 14.Latching arms 16 engage appropriate mechanical linkages (not shown) onrear portion 12 for holding camera back 10 to rear portion 12. Anaperture 18 is provided within camera back 10 for permitting viewing andsubsequently, for permitting exposure through back 10. A viewing screen20 is adapted to fit behind back 10 and over aperture 18. Viewing screen20 may be any one of a variety of screens known in the photographicfield.

Viewing screen 20 is fit onto camera back 10 by insetting it into back10 from the left to the right as viewed in FIG. 1. Provided on thelateral sides 22 of screen 20 are two pins 24. When screen 20 isinserted into back 10, pins 24 slip under a pair of torsion bars 26located on the rearward side of adapter assembly 14. Torsion bars 26 arebiased into adapter assembly 14 and are attached to adapter assembly 14through two screws 28 located in a torsion plate 30. When screen 20 isfit in adapter assembly 14 (See FIG. 1) pins 24 are engaged by a pair ofnotches 32 formed in torsion bars 26. The engagement between pins 24 andnotches 32 generally locates viewing screen 20 with respect to adapterassembly 14 and aperture 18. Exact location of screen 20 is accomplishedby pins 24 falling into two slots 21 located on the top and bottomportions of assembly 14. Additionally, due to the forward biasing (asviewed in FIG. 2) of the torsion bars 26 into adapter assembly 14, pins24 and consequently, viewing screen 20, are biased into engagement withadapter assembly 14.

An actuation arm, shown generally at 34, is located along the bottomportion of adapter assembly 14. Actuation arm 34 includes a hollowrectangular bar portion 36 and an actuation finger portion 38 extendingtherefrom. Located within hollow rectangular bar portion 36 is acompression spring 40. Compression spring 40 extends between an end 42of portion 36 to a boss 44 located inside bar portion 36. A pair of rollpins 46 are provided along the length of bar portion 36 of arm 34. Pins46 extend through lateral slots (not shown) in bar portion 36 and a pairof boss members 44 fixedly attached to adapter assembly 14. Configuredas such, actuator arm 34 is able to move laterally in the directionsdenoted by arrow 56. Connected to end 42 of bar portion 36 is aconventional cable release 48. Cable 48 extends through a wall section50 and two nuts 52 to a shutter assembly 54 (See FIG. 3).

As may be evidenced from FIG. 1, actuation finger portion 38 extendsinto an area already occupied by viewing screen 20. For this reason anotch 56 is provided in viewing screen 20 for accommodating fingerportion 38 when the viewing screen is on assembly 14. (See FIG. 2)

Operation The initial step in the operation of the camera incorporatingthe present invention is focusing. The focusing screen is connected toassembly 14 by fitting screen 20 into assembly 14 from the left to theright as viewed in FlG. 1. Pins 24 are engaged by torsion bars 26 andare captured by notches 32 and slots 21. When properly set, the focusingscreen 20 is directly over aperture 18. This status is best shown inFIG. 1. As may be evidenced from the foregoing, actuation arm 34 remainsin a position in which finger portion 38 is in notch 56. Actuation arm34 is maintained in this leftward position by compression spring 40.Specifically, spring 40 is butted up between boss 44 and end 42 of bar36. Accordingly, spring 40 forces end 42 and bar 36 to the left asviewed in FIG. 1. When bar 36 is in this position, cable 48 is in anextended status and, due to its connection with shutter 54, actuatesshutter 54 to retain the shutter blades 58 in a fully opened position incorrespondence with normal shutter operating procedures known in theart. The shutter blades 58 will remain in this opened position for aslong as bar portion 36 is in the left position shown in FIG. 1. As aresult, all focusing will be carried out in the obviously desirablefully open shutter condition. It is in this condition that maximumfocusing light is passed from the image through the shutter to the eyeof the camera operator. When focusing has been accomplished, the filmcarrier (not shown) is introduced to the cameras back adapter assembly14.

The camers film carrier may be one of a variety of sheet or roll filmholders known in the art. In all cases, however, the film carrier has arectangular shape and is of a size suitable for use with adapterassembly 14. Adaption of the film carrier to the adapter assembly isaccomplished in a simple one step process. One edge of the viewingscreen 20 is lifted away from adapter as sembly 14 by grasping eitherone of two corners 60 of viewing screen 20 and pulling it away fromassembly 14. Next, the film carrier is inserted under viewing screen 20from the left to the right (See FIG. 1) and is pushed to the right untilthe leading edge of the film carrier engages finger 38. As the filmcarrier does not have a notch, further movement of the carrier displacesfinger 38 to the right. The film carrier is moved until it is properlyseated under viewing screen 20 and the exposure aperture of the filmcarrier is aligned with the aperture 18 of the adapter assembly 14. Twobosses 62 and 64 prevent the film carrier from being moved completelyout of the assembly 14. Proper lateral orientation of the film carrieris accomplished by the engagement between a trough 63 located onassembly 14 and a suitably sized rod (not shown) located on the bottomof the film carrier. Moreover, proper vertical orientation of the filmcarrier is carried out by two orienting rails 66 and 68 located belowand above aperture 18, respectively. When the film carrier is placedunder viewing screen 20, torsion bars 26 are expanded and hold bothviewing screen 20 and the film carrier downward into engagement withadapter assembly 14. Accordingly, a lighttight seal around the filmcarrier is provided.

As mentioned previously, the movement of the film carrier into itsexposure position displaces finger 38 to the right. This movement offinger 38 moves actuation arm 34 to the right against the bias providedby cornpression spring 40. Due to the connection between end 42 of barportion 36 and cable 48, movement of actuation arm 34 to the rightreleases the cable end at shutter 54 thereby closing shutter blades 58.An exposure may now be taken using a conventional shutter release 70coupled to shutter 54. Actuation of shutter release 70 will reopenshutter blades 58 to their preset exposure setting and light will passthrough aperture 18 and onto the film contained within the film carrier.

Should focusing be desired again, the film carrier. is removed in thereverse direction it was installed and focusing screen 20 is retumedtoits forward position in which it abuts adapter assembly 14. Removal ofthe film carrier permits finger 38 and actuation arm 34 to return to theleft under the bias provided by compression spring 40. When actuationarm 34 has returned, cable 48 is again extended and shutter blades 58will open to their full aperture focusing position.

It should be self evident that the automatic shutter control of thepresent invention obviates the need for manually opening the shutter toits fully open position prior to the focusing operation of the camera.As such, the automatic shutter control of the present invention utilizesa simple and uncomplicated mechanism which minimizes exposure errors forwhich the camera operator had been previously responsible.

Since certain changes may be made in the above apparatus withoutdeparting from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:

1. In a photographic camera having a lens, a shutter, a viewing screen,a removable film holder and means on said camera for accepting said filmholder, shutter control means for retaining said shutter in an openstatus when said film holder is removed from said camera and for closingsaid shutter when said film holder is inserted in said film holderaccepting means, said shutter control means comprising:

arm means, a portion of which is positioned in the path of insertion ofsaid film holder, said arm means being movable by said film holder froma first position in which said arm means is in said path of insertion toa second position in which said arm means is out of said path ofinsertion when said film holder is inserted in said film holderaccepting means;

compression spring means connected to said arm means, said compressionspring means being operative to bias said arm means into said path ofinsertion of said film holder; and

cable means, directly connecting said arm means with said shutter; saidcable means being operative to open said shutter when said arm means isin said first position and to close said shutter to a predeterminedposition when said arm means is in said second position, said viewingscreen being releasably retained on said camera by said means foraccepting said film holder, said viewing screen having means foraccommodating said portion of said arm means positioned in said path ofinsertion of said film holder for preventing movement of said arm meansfrom said first position to said second position when said viewingscreen is positioned on said camera and is engageably contacted by saidmeans for accepting said film holder.

2. The shutter control means of claim 1 in which said means foraccommodating said portion of said arm means positioned in said path ofinsertion of said film holder is a notch.

3. The shutter control means of claim 2 in which said film holder breakssaid engageable contact between said viewing screen and said means foraccepting said film holder when said film holder is inserted in saidfilm holder accepting means.

4. The shutter control means of claim 1 in which said actuation cablerelease.

1. In a photographic camera having a lens, a shutter, a viewing screen,a removable film holder and means on said camera for accepting said filmholder, shutter control means for retaining said shutter in an openstatus when said film holder is removed from said camera and for closingsaid shutter when said film holder is inserted in said film holderaccepting means, said shutter control means comprising: arm means, aportion of which is positioned in the path of insertion of said filmholder, said arm means being movable by said film holder from a firstposition in which said arm means is in said path of insertion to asecond position in which said arm means is out of said path of insertionwhen said film holder is inserted in said film holder accepting means;compression spring means connected to said arm means, said compressionspring means being operative to bias said arm means into said path ofinsertion of said film holder; and cable means, directly connecting saidarm means with said shutter; said cable means being operative to opensaid shutter when said arm means is in said first position and to closesaid shutter to a predetermined position when said arm means is in saidsecond position, said viewing screen being releasably retained on saidcamera by said means for accepting said film holder, said viewing screenhaving means for accommodating said portion of said arm means positionedin said path of insertion of said film holder for preventing movement ofsaid arm means from said first position to said second position whensaid viewing screen is positioned on said camera and is engageablycontacted by said means for accepting said film holder.
 2. The shuttercontrol means of claim 1 in which said means for accommodating saidportion of said arm means positioned in said path of insertion of saidfilm holder is a notch.
 3. The shutter control means of claim 2 in whichsaid film holder breaks said engageable contact between said viewingscreen and said means for accepting said film holder when said filmholder is inserted in said film holder accepting means.
 4. The shuttercontrol means of claim 1 in which said compression spring means ispositioned in said arm means, said compression spring means beingcompressed when said arm means is moved to said second position, by saidfilm holder, said compression spring means being operative to returnsaid arm means to said first position when said film holder is removedfrom said film holder accepting means.
 5. The shutter control means ofclaim 1 in which said shutter includes an exposure actuationt cablerelease, said cable means being independent of said exposure actuationcable release.